Search for Long-Lived Particles Decaying in the CMS End Cap Muon Detectors in Proton-Proton Collisions at

Physical Review Letters

A search for dark matter in events with a displaced nonresonant muon pair and missing transverse momentum is presented. The analysis is performed using an integrated luminosity of 138 fb− 1 of proton-proton (p p) collision data at a center-of-mass energy of 13 TeV produced by the LHC in 2016–2018. No significant excess over the predicted backgrounds is observed. Upper limits are set on the product of the inelastic dark matter production cross section σ (p p→ A′→ χ 1 χ 2) and the decay branching fraction B (χ 2→ χ 1 μ+ μ−), where A′ is a dark photon and χ 1 and χ 2 are states in the dark sector with near mass degeneracy. This is the first dedicated collider search for inelastic dark matter.

arXiv preprint arXiv:2402.05523

The first observation of the decay is reported with high significance using proton-proton collision data, corresponding to an integrated luminosity of 9fb, collected with the LHCb detector at centre-of-mass energies of 7, 8, and 13 TeV. The ratio of its branching fraction relative to the channel is measured to be $$ \frac{ {\cal{B}}( B_c^+ \to J/\psi \pi^+\pi^0 ) } { {\cal{B}}( B_c^+ \to J/\psi \pi^+ ) } = 2.80 \pm 0.15 \pm 0.11 \pm 0.16 \,, $$ where the first uncertainty is statistical, the second systematic and the third related to imprecise knowledge of the branching fractions for and decays, which are used to determine the detection efficiency. The mass spectrum is found to be consistent with the dominance of an intermediate contribution in accordance with a model based on QCD factorisation.

Malnutrition, often termed “hidden hunger,” represents a pervasive global issue carrying significant implications for health, development, and socioeconomic conditions. Addressing the challenge of inadequate essential nutrients, despite sufficient caloric intake, is crucial. Biofortification emerges as a promising solution by enhance the presence of vital nutrients like iron, zinc, iodine, and vitamin A in edible parts of different crop plants. Crop biofortification can be attained through either agronomic methods or genetic breeding techniques. Agronomic strategies for biofortification encompass the application of mineral fertilizers through foliar or soil methods, as well as leveraging microbe-mediated mechanisms to enhance nutrient uptake. On the other hand, genetic biofortification involves the strategic crossing of plants to achieve a desired combination of genes, promoting balanced nutrient uptake and bioavailability …

Physics Letters B

Measurements of the elliptic (v 2) and triangular (v 3) azimuthal anisotropy coefficients are presented for Image 1 mesons produced in Image 2 hadron decays (nonprompt Image 1 mesons) in lead-lead collisions at s NN= 5.02 TeV. The results are compared with previously published charm meson anisotropies measured using prompt Image 1 mesons. The data were collected with the CMS detector in 2018 with an integrated luminosity of 0.58 nb− 1. Azimuthal anisotropy is sensitive to the interactions of quarks with the hot and dense medium created in heavy ion collisions. Comparing results for prompt and nonprompt Image 1 mesons can assist in understanding the mass dependence of these interactions. The nonprompt results show lower magnitudes of v 2 and v 3 and weaker dependences on the meson transverse momentum and collision centrality than those found for prompt Image 1 mesons. The results are …

arXiv preprint arXiv:2404.16082

A measurement is presented of a ratio observable that provides a measure of the azimuthal correlations among jets with large transverse momentum . This observable is measured in multijet events over the range of = 360-3170 GeV based on data collected by the CMS experiment in proton-proton collisions at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 134 fb. The results are compared with predictions from Monte Carlo parton-shower event generator simulations, as well as with fixed-order perturbative quantum chromodynamics (pQCD) predictions at next-to-leading-order (NLO) accuracy obtained with different parton distribution functions (PDFs) and corrected for nonperturbative and electroweak effects. Data and theory agree within uncertainties. From the comparison of the measured observable with the pQCD prediction obtained with the NNPDF3.1 NLO PDFs, the strong coupling at the Z boson mass scale is = 0.1177 0.0013 (exp) (theo) = 0.1177, where the total uncertainty is dominated by the scale dependence of the fixed-order predictions. A test of the running of in the TeV region shows no deviation from the expected NLO pQCD behaviour.

A search is described for the production of a pair of bottom-type vector-like quarks (B VLQs) with mass greater than 1000 GeV. Each B VLQ decays into a b quark and a Higgs boson, a b quark and a Z boson, or a t quark and a W boson. This analysis considers both fully hadronic final states and those containing a charged lepton pair from a Z boson decay. The products of the H bb boson decay and of the hadronic Z or W boson decays can be resolved as two distinct jets or merged into a single jet, so the final states are classified by the number of reconstructed jets. The analysis uses data corresponding to an integrated luminosity of 138 fb collected in proton-proton collisions at = 13 TeV with the CMS detector at the LHC from 2016 to 2018. No excess over the expected background is observed. Lower limits are set on the B VLQ mass at 95% confidence level. These depend on the B VLQ branching fractions and are 1570 and 1540 GeV for 100% B bH and 100% B bZ, respectively. In most cases, the mass limits obtained exceed previous limits by at least 100 GeV.

Diboson production in association with jets is studied in the fully leptonic final states, pp (Z)(Z/)+jets 22+jets, ( = e or ) in proton-proton collisions at a center-of-mass energy of 13 TeV. The data sample corresponds to an integrated luminosity of 138 fb collected with the CMS detector at the LHC. Differential distributions and normalized differential cross sections are measured as a function of jet multiplicity, transverse momentum , pseudorapidity , invariant mass and of the highest- and second-highest- jets, and as a function of invariant mass of the four-lepton system for events with various jet multiplicities. These differential cross sections are compared with theoretical predictions that mostly agree with the experimental data. However, in a few regions we observe discrepancies between the predicted and measured values. Further improvement of the predictions is required to describe the ZZ+jets production in the whole phase space.

2021-10-15 Assigned to UNIVERSITY OF PITTSBURGH-OF THE COMMONWEALTH SYSTEM OF HIGHER EDUCATION reassignment UNIVERSITY OF PITTSBURGH-OF THE COMMONWEALTH SYSTEM OF HIGHER EDUCATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KUMTA, PRASHANT N., KUNJUKUNJU, Sangeetha, LEE, Boeun, OSTROWSKI, NICOLE J., ROY, ABHIJIT, RAMANTHAN, MADHUMATI2021-10-18 Assigned to UNIVERSITY OF PITTSBURGH-OF THE COMMONWEALTH SYSTEM OF HIGHER EDUCATION reassignment UNIVERSITY OF PITTSBURGH-OF THE COMMONWEALTH SYSTEM OF HIGHER EDUCATION CORRECTIVE ASSIGNMENT TO CORRECT THE THE ZIP CODE OF THE RESPONDENT PREVIOUSLY RECORDED AT REEL: 057805 FRAME: 0502. ASSIGNOR (S) HEREBY CONFIRMS THE ASSIGNMENT. Assignors …

A search for the production of long-lived particles in proton-proton collisions at a center-of-mass energy of 13 TeV at the CERN LHC is presented. The search is based on data collected by the CMS experiment in 2016-2018, corresponding to a total integrated luminosity of 137 fb. This search is designed to be sensitive to long-lived particles with mean proper decay lengths between 0.1 and 1000 m, whose decay products produce a final state with at least one displaced vertex and missing transverse momentum. A machine learning algorithm, which improves the background rejection power by more than an order of magnitude, is applied to improve the sensitivity. The observation is consistent with the standard model background prediction, and the results are used to constrain split supersymmetry (SUSY) and gauge-mediated SUSY breaking models with different gluino mean proper decay lengths and masses. This search is the first CMS search that shows sensitivity to hadronically decaying long-lived particles from signals with mass differences between the gluino and neutralino below 100 GeV. It sets the most stringent limits to date for split-SUSY models and gauge-mediated SUSY breaking models with gluino proper decay length less than 6 m.

Physics Letters B

Measurements of the elliptic (v 2) and triangular (v 3) azimuthal anisotropy coefficients are presented for Image 1 mesons produced in Image 2 hadron decays (nonprompt Image 1 mesons) in lead-lead collisions at s NN= 5.02 TeV. The results are compared with previously published charm meson anisotropies measured using prompt Image 1 mesons. The data were collected with the CMS detector in 2018 with an integrated luminosity of 0.58 nb− 1. Azimuthal anisotropy is sensitive to the interactions of quarks with the hot and dense medium created in heavy ion collisions. Comparing results for prompt and nonprompt Image 1 mesons can assist in understanding the mass dependence of these interactions. The nonprompt results show lower magnitudes of v 2 and v 3 and weaker dependences on the meson transverse momentum and collision centrality than those found for prompt Image 1 mesons. The results are …

An inclusive search for long-lived exotic particles (LLPs) decaying to final states with a pair of muons is presented. The search uses data corresponding to an integrated luminosity of 36.6 fb collected by the CMS experiment from the proton-proton collisions at = 13.6 TeV in 2022, the first year of Run 3 of the CERN LHC. The experimental signature is a pair of oppositely charged muons originating from a common vertex spatially separated from the proton-proton interaction point by distances ranging from several hundred m to several meters. The sensitivity of the search benefits from new triggers for displaced dimuons developed for Run 3. The results are interpreted in the framework of the hidden Abelian Higgs model, in which the Higgs boson decays to a pair of long-lived dark photons, and of an -parity violating supersymmetry model, in which long-lived neutralinos decay to a pair of muons and a neutrino. The limits set on these models are the most stringent to date in wide regions of lifetimes for LLPs with masses larger than 10 GeV.

arXiv preprint arXiv:2404.17377

The performance of muon tracking, identification, triggering, momentum resolution, and momentum scale has been studied with the CMS detector at the LHC using data collected at = 5.02 TeV in proton-proton (pp) and lead-lead (PbPb) collisions in 2017 and 2018, respectively, and at = 8.16 TeV in proton-lead (pPb) collisions in 2016. Muon efficiencies, momentum resolutions, and momentum scales are compared by focusing on how the muon reconstruction performance varies from relatively small occupancy pp collisions to the larger occupancies of pPb collisions and, finally, to the highest track multiplicity PbPb collisions. We find the efficiencies of muon tracking, identification, and triggering to be above 90% throughout most of the track multiplicity range. The momentum resolution and scale are unaffected by the detector occupancy. The excellent muon reconstruction of the CMS detector enables precision studies across all available collision systems.

A search is described for the production of a pair of bottom-type vector-like quarks (B VLQs) with mass greater than 1000 GeV. Each B VLQ decays into a b quark and a Higgs boson, a b quark and a Z boson, or a t quark and a W boson. This analysis considers both fully hadronic final states and those containing a charged lepton pair from a Z boson decay. The products of the H bb boson decay and of the hadronic Z or W boson decays can be resolved as two distinct jets or merged into a single jet, so the final states are classified by the number of reconstructed jets. The analysis uses data corresponding to an integrated luminosity of 138 fb collected in proton-proton collisions at = 13 TeV with the CMS detector at the LHC from 2016 to 2018. No excess over the expected background is observed. Lower limits are set on the B VLQ mass at 95% confidence level. These depend on the B VLQ branching fractions and are 1570 and 1540 GeV for 100% B bH and 100% B bZ, respectively. In most cases, the mass limits obtained exceed previous limits by at least 100 GeV.

Pakistan Languages and Humanities Review

People use language for different social practices, for different purposes and in different contexts. Discourse analysis is a vast and deep field of study which examines these social practices to understand the hidden meanings behind the text. The objective of this paper was to analyze a simple but very strong and amazing phrase ‘absolutely not’by the Pakistani PM in a particular context. The PM used this phrase during an interview with Jonathan Swan on HBO on Saturday, June 19, 2021 when he was asked a question about giving military bases to the US in Pakistan for targeted operations in Afghanistan. The worldwide print and electronic media discussed and interpreted this amazing phrase ‘absolutely not’focusing on the past Pak-US relationships and its impacts on future politics in the region, but this article tried to clarify and highlight some precise meanings attached to this amazing term. This ‘absolutely not’also takes on symbolic meanings. It shows the PM’s moral standpoint against anti-peace-keeping policies in the region, shows its power and impact on the present and future policies to establish regional peace, and it shows the PM’s love for peace in the region and also the possible consequences as stated in the research questions. Fairclough’s model in CDA has been used to analyze this amazing ‘absolutely not’and contribute to existing knowledge by filling a research gap. The present economic and political ground realities are a true picture of this critical analysis, and more research of this ‘absolutely not’should be conducted in the future according to the upcoming ground realities in the region.

arXiv preprint arXiv:2403.01313

The top quark mass is one of the most intriguing parameters of the standard model (SM). Its value indicates a Yukawa coupling close to unity, and the resulting strong ties to the Higgs physics make the top quark mass a crucial ingredient for understanding essential aspects of the electroweak sector of the SM. While it is such an important parameter of the SM, its measurement and interpretation in terms of the Lagrangian parameter are challenging. The CMS Collaboration has performed multiple measurements of the top quark mass, addressing these challenges from different angles: highly precise `direct' measurements, using the top quark decay products, as well as `indirect' measurements aiming at accurate interpretations in terms of the Lagrangian parameter. Recent mass measurements using Lorentz-boosted top quarks are particularly promising, opening a new avenue of measurements based on top quark decay products contained in a single particle jet, with superior prospects for accurate theoretical interpretations. Moreover, dedicated studies of the dominant uncertainties in the modelling of the signal processes have been performed. This review offers the first comprehensive overview of these measurements performed by the CMS Collaboration using the data collected at centre-of-mass energies of 7, 8, and 13 TeV.

Physics Letters B

The azimuthal anisotropy of mesons in high-multiplicity proton-lead collisions is studied using data collected by the CMS experiment at a nucleon-nucleon center-of-mass energy of 8.16 TeV. The mesons are reconstructed using their dimuon decay channel. The anisotropy is characterized by the second Fourier harmonic coefficients, found using a two-particle correlation technique, in which the mesons are correlated with charged hadrons. A large pseudorapidity gap is used to suppress short-range correlations. Nonflow contamination from the dijet background is removed using a low-multiplicity subtraction method, and the results are presented as a function of transverse momentum. The azimuthal anisotropies are smaller than those found for charmonia in proton-lead collisions at the same collision energy, but are consistent with values found for mesons in lead-lead interactions at a nucleon-nucleon center-of …

Annals of PIMS-Shaheed Zulfiqar Ali Bhutto Medical University

Objective: The objective was to understand association of sleep and anxiety with pain during root canal therapy.Methods: Total of 500 patients were included, August-December 2020, who were seeking endodontic care at Islam Dental College, Sialkot. Sleep and anxiety was documented by the number sleep hours. Numeric pain scale was used to document pain.Results: The independent variable, anxiety, reported pain on the visual analog scale as: Mild (M= 2.01, SD=. 853, n= 250), Moderate (M= 2.86, SD=. 870, n= 158) and Severe (M= 3.42, SD=. 952, n= 92) and the second independent variable, sleep, reported pain on the visual analog scale as: Mild (M= 1.49, SD=. 501, n= 250), Moderate (M= 1.47, SD=. 501, n= 158) and Severe (M= 1.43, SD=. 498, n= 92). Levene’s Test for anxiety showed the variance of homogeneity, F.(2., 497)= 5.005, p=. 007. Levene’s Test for sleep showed the variance of homogeneity …

Journal of High Energy Physics

The production of prompt baryons is measured via the exclusive decay channel at a center-of-mass energy per nucleon pair of 5.02 TeV, using proton-proton (pp) and lead-lead (PbPb) collision data collected by the CMS experiment at the CERN LHC. The pp and PbPb data were obtained in 2017 and 2018 with integrated luminosities of 252 and 0.607 nb− 1, respectively. The measurements are performed within the rapidity interval| y|< 1 with transverse momentum (p T) ranges of 3–30 and 6–40 GeV/c for pp and PbPb collisions, respectively. Compared to the yields in pp collisions scaled by the expected number of nucleon-nucleon interactions, the observed yields of with p T> 10 GeV/c are strongly suppressed in PbPb collisions. The level of suppression depends significantly on the collision centrality. The/D 0 production ratio is similar in PbPb and pp collisions at p T> 10 GeV/c, suggesting that …